Method for cracking hydrocarbons in the presence of the halogen, bromine, and iodine, and a chlorinated unsaturated aliphatic organic compound



. PERCENT PRESSURE INCREASE March 1 1, 1947. H. o. FOLKINS 7,

METHOD FOR CRACKING HYDROCARBONS IN THE PRESENCE OF THE HALOGEN, BROMINE, AND IODINE, AND A CHLORINATED UNSATURATED ALIPHATIC ORGANIC COMPOUND Filed May 25, 1945 4 Sheets-Sheet l TL-BUTANE DECOMPOSITION AT SOO C '1. LA K RU l INE AT 0. 6

7 9 IO TIME (MINUTES) 1 N VEN TOR.

ATTORNEY Hill/is 0. Fol/kins PER CENT PRESSURE INCREASE March 11,1947. o, o s 2,417,105

METHOD FOR CRACKING HYDRGCARBONS IN THE PRESENCE OF THE HALOGEN, BROMINE, AND IODINE, AND A CHLORINATED UNSATURATED ALIPHATIC ORGANIC COMPOUND Filed May 25, 1945 4 Sheets-Sheet 2 Tb-BUTANE DECOMPOSITION AT 500C o 2 a 4 5 e 1 a 9 lo I: l2 l3 I4- 15 I6 17 1e I9 20 TIME (MINUTES) I INVENTOR. Hill/is QFoIJzi/ns 1 y {M 14/- L ATTORNEY March 11 1947.

PERCENT PRESSURE INCREACE H. o. FOLKINS 7, 5 METHOD FOR CRACKING'HYDROGARBONS, IN THE PRESENCE OF THE HALOGEN, BROMINE, AND IODINE, AND A CHLORINATED UNSA'IURATED ALIPHATIC ORGANIC COMPOUND Filed May 25, 1945 4 Sheets-Sheet 3 n-BUTANE DECOMPOSITION AT 500C 6 7 B 9 l0 ll TIME (MINUTES) INVENTOR. Hill/is Fol/kins- 11325 BY ZZWJ 4/ A;

ATTORAEY I PERCENT PRESSURE INCREASE Mar h 1 1947. H. O.FOLKINS METHOD FOR CRACKING HYDROCARBONS IN THE PRESENCE OF THE HALOGEN, BROMINE, AND IODINE, AND A CHLORINATED UNSATURATED ALIPI-IATIC ORGANIC COMROUND Filed May 25, 1945 4 Sheets-Sheet 4 11,-BUTANE DECOMPOSITION AT 500C 0 l 2 3 4 5 6 7 a 9 10 ll I2 l3 l4 l5 l5 I7 l8 I9 20 TIME (MINUTES) I INVENTOR. Hill/is aFol/kins Jug. 4 BY ATTORN Y latentecl Mar. 11, 1947 METHOD FOR CRACKING HYDROCARBONS IN THE PRESENCE BROMINE, AND IODI OF THE HALOGEN, NE, AND A CHLOE-IN! ATED UNSATURATED ALIPHATIC R- GANIC COMPOUND Hillis O. Folkins, Skokie, 111., assignor to The Pure Oil Company, Chicago, 111., a corporation of Ohio Application May 25, 1945, Serial No. 595;712 13 Claims. (Cl. ,19 6.5,2)

This invention relates to cracking of hydrocarhens, and is more particularly concerned with a method for converting higher boiling hydrocarbons into lower boiling hydrocarbons and for making unsaturated hydrocarbons from saturated hydrocarbons.

I have discovered .that if thermal conversion of hydrocarbons is carried out in the presence of a small amount of an organic compound havin a chlorinated unsaturated aliphatic group, and of a small amount of bromine or iodine, the cracking of the hydrocarbon is greatly accelerated so that it is possible to obtain larger yields of cracked hydrocarbonsthan it is possible to obtain in thermal cracking of hydrocarbons Without sensitizer under the same time-temperaturepressure conditions, and it is possible to obtain yields at lower temperatures commensurate with yields at higher temperatures without sensitizers.

The invention is applicable to either batch or continuous methods of cracking. In continuous cracking methods, by operating under usual thermal cracking conditions in the presence of a sensitizer, not only can higher yields be obtained but higher octane gasoline can be produced. By using the sensitizer a larger through-put of charging stock to a given size unit can be effected because of the acceleration in the cracking reaction caused by the sensitizer.

An object of the invention is to provide a method for the conversion of hydrocarbons.

Another object of the invention is to provide a method for accelerating cracking of hydrocars bons.

Still another object of the invention is to provide a method to increase octane number of motor fuel made by cracking of hydrocarbons.

A further object of the invention is to provide a sensitizer which will accelerate the decomposition of hydrocarbons.

A still further object of the inventionis to provide a method to improve the thermal cracking of hydrocarbons.

Other objects of the invention will become apparent from the following disclosure and accompanying drawings, of which Figure l is a graphical representation of data showing the unexpected results obtained from using a combination of bromine and allyl chloride as cracking sensitizer.

Figure 2 is a graphical representation of data showing the unexpected results obtained from using a combination of bromine and iso-crotyl chloride as sensitizer.

til

Figure 3 is a graphical representation showing the unexpected results obtainedirom using a combination of bromine and beta-methylallyl chloride a racking sensitizer; an

Figure 4 is a graphical representation showing the unexpected results obtained from using a combination of bromine and trichlor ethylene as cracking sensitizer.

In accordance with my invention a small amount of a chlorinated, unsaturated, aliphatic organic compound, and more particularly chlorinated, unsaturated, aliphatic hydrocarbons, such as allyl chloride, iso-crotyl chloride, betamethylallyl chloride, trichlor ethylene and carbon dichloride, and a small amount of bromine and/or iodine are mixed with hydrocarbons subjected to decomposition. The compound containing the chlorinated, unsaturated, aliphatic group and the halogen may be mixed with the hydrocarbons.

prior to charging them to the reaction zone, or they may be injected directly into the reaction zone. The total ,sensitizer mixture may be used in concentrations from approximately .055 mole per cent to 5 mole per cent based on the total charge and should contain not less than about .005 mole per cent of bromine and/0r iodine and not less than about .05 mole per cent of the organic compound containing the chlorinated, unsaturated, aliphatic group. Higher concentrations of sensitizers may be used, but within the limits above set forth the reaction progresses rapidly without causing accumulation of undesirably large amounts of sensitizers or their decomposition products in the motor fuel or other products which it is desired to produce. In the experimental work which has been performed a mixture containing from .03 to 2 mole per cent of bromine and from .25 to 2 mole per cent of an organic compound containing a Chlorinated, unsaturated, aliphatic group has been found to give unusually good results.

The invention is useful in conjunction with conventional typesof thermal cracking in which the hydrocarbons are cracked at temperatures within the range of approximately 375 C. to 750 0., and is applicable to conversion of hydrocarbon gases such as propane and butane, s well as to the conversion of liquid hydrocarbons such as heavy naphtha, kerosene and gas oil into gasoline or lower boiling hydrocarbons. -'I he combination of the bromine and/or iodine with the or.-

eanic co ou d conta ning a c orinat d, n-

saturated, aliphatic group accelerates the crack ing reaction to an extent far in excess of that which would be expected from the additive effect unsaturated, aliphatic hydrocarthereafter pressure readde at 2 minute the end of cent pressure increases a pressure reading was made 0.5 m

nt pressure increases were plotted In the table the figures given under Time in minutes for AP of 25% are om curves based on recorded presinning of the run until 6 minutes thereafter,

eriod from 20 to 40 minutes and at minsensitizer, and other runs were made using only a chlorinated bon and only bromine as sensitizer.

In each of the runs the initial pressure was 5 calculated,

ute after the run began, ings were made at intervals of 1 minute from the beg from that point readings were ma intervals until minutes after the run began, and when it was necessary to run in excess of 20 minutes to obtain per cent pressure increase, readings were taken at 5 minute intervals during the p ute intervals beyond minutes until the run. The figures appearing in the table for 5 per cent and 12.5 per were taken from curves of individual runs in which per ce against time. the heading in some cases recorded and in other cases are interpolated fr sures because in certain runs the pressure rose 0 rapidly to obtain a reading at the exact point. Results of some of the runs which were made are set forth in the following table Table 9 09572195 4 8 8 5 2 700233852 3 8 1 9 3 27821 9 2 3 7 6 6 452 5 5 5 6 5 6 6 515 446 06 0 5 6 5 2 5 5 555 5 5 6 i 5 5 m m 41067941 4 5 8 4 5 0 03975189 4 5 5 7 8 8 1980 5 0 4 8 6 7 m m LLLQQOJLL L 0 0 0 0 0 L0 0 0 0L0 0 0 0 0 0 0 0 1001 0 0 0 0 0 0 e c r m- 13301000 0 1 1 l 0 1 10432113 0 1 o 1 1 0 42 2 6 2 1 4 2 4 k W 00 00 00 000 0 0 0 0 000 000 0000 0 0 0 0 000000 0 0 0 0 0 0 m s 44178073 1 5 2 O 1 2 17478203 1 0 7 8 0 8 1124 6 2 2 5 5 3 c t 2 23 22 3 2 3 6 3 3333 3 w ed M H% M. 2 mm 2 22%M22 2 M 2 2 2 2 2222 2 M mm M. 0 n r U P 8 13 02001 1 1 1 0 2 0 10312330 3 1 0 3 2 1 2112 2 1 1 0 o 0 m 0 0 0 0 0000 0 0 0 0 0 0 00 000000 0 0 0 0 0 0 0000 0 0 0 0 0 0 A r a m56207746 8 3 2 3 8 m62201237 8 7 1 9 7 5050 5 7 3 0 7 0 W m mnmmanw m1222 0 111111 m u u u H0 L L 8 4 am 4 1 .L23 2 6 L 7 7 3 m m MM W m w m "5569 1 U 2 3 3 4 1 g 2 2 3 2 2 2 l A 1 m .1 .m "27412873 9 0 0 2 5 76739104 9 2 9 2 4 584 7 9 6 1 9 7 0 5&57.1L206&901 w W mm H M M M w 00 B U m 4 3 4 1 u 3 0 7 4 4 2 S n n 5 2 n 7 0 5 0 3 nun 53 2 5 3 2 8 0 9m4 Qm9m:m0 53L&4 0m3w&43&2 080054553 H1111 655 using norutane had tion tem- 10 f a vacture with se sometion was 25 AP of- 8005125 9 1 9 05517375 0 co 8 005420320 L 0 0 2 11 n so 9 9 3 6 5 0 2004 1 9 8 9 9 1 0 0 0 0 L t a temperature the reaction the tempera- Time in minutes for ns were all made 3 1812 99 0. 119019050590722410584 7-fi vn cm4ooo mw W 2 2 7w 72055073 2 1 2 1 337102 1 1 1 1 3 the effectiveness of the below 0.001 mm 0 e v e s I s s 1 1 I I W 6 &LL0 &33 00 0 0 00001107660000007443000000 1 1 2 11 1111112111} 11171111111} 5 55 5 5 555550550550 550555550550550 m .2%% 2 "%2 .fl2: o -222 .2 .2 .22 .2 .222 .2 .2 .22 1 .0110 .0 .1 .0 .111 .1 1 .1 .0 .10 .1 .11 .01 .0 .10 .1 .11 .0 000 0 00 0 0 00 000 0 0 0 0 000 0 0 0 If be P ged to the evacuated vessel until the 5 Identification In order to demonstate erature and then evacuated by means 0 ressure. The reaction was permitted to proceed A number of runs were also made without any of the chlorinated compound and the bromine and/or iodine alone.

combination sensitizer in the cracking of hydrocarbons a number of runs were made mal butane as charging stock. The b a purity of 99 per cent. The ru in a Pyrex glass reaction. vessel a of 500 C. Before starting each run vessel was heated to the desired reac uum pump to a pressure mercury. Sufiicient butane in admix the desired amount of sensitizer composition was then char pressure in the vessel approximated atmospheric p in the closed reaction vessel while ture was maintained at 500 C. until a pressure increase of 25 per cent above the initial pressure 20 was observed, whereupon the reaction gases were rapidly removed from the reactor, and analyzed. In some runs where the acceleration in reaction was extremely rapid the pressure increa what exceeded 25 per cent before the reac terminated.

Run No.

See footnotes at end of table,

Time iAHPmiDEtOS for sensitizzii iolpfactorfor Products, mole per cent Run No. Identification gfgg v V 5% 12.5% 25% 5% 12.5% 25% Acids Unsats. H0 Residue *Average of several runs. rAlIyl chloride.

The sensitization factors recorded in the table are obtained by dividing the time required for a particular pressure increase without sensitizer by the time required for the same increase with sensitizer.

From the table it is evident that allyl chloride, iso-crotyl chloride, beta-methylallyl chloride and trichlor ethylene have a small sensitizing effect on the cracking reaction when used alone. It is also apparent that bromine when used alone has a sensitizing effect on the cracking reaction which is somewhat greater than that of the chlorinated, unsaturated hydrocarbons. However, by using a combination of bromine with a chlorinated, unsaturated, aliphatic hydrocarbon the sensitizing effect increases remarkably. As an example, 0.25 mole per cent of bromine alone (run 3) gave a sensitization factor of 4.6, for a 25 percent pressure increase. Allyl chloride when present in the amount of 1 per cent (run 6) gave a sensitization factor for a 25 per cent pressure increase of 2.7. However, when a mixture of 0.25 mole per cent of bromine and 1 mole per cent of allyl chloride (run 13) was used the sensitization factor for a 25 per cent pressure increase was 25.3.

An even more striking example exists in the case of iso-crotyl chloride. One per cent of bro- ,mine alone (run 19) gave a sensitization factor for a 25 per cent pressure increase of 8. Isocrotyl chloride in the amount of 0.25 mole per cent (run 20) gave a sensitization factor of 1.1 for a pressure increase of per cent. However, when 0.25 mole per cent of iso-crotyl chloride was mixed with 1 per cent of bromine (run 27) the sensitization factor for a 25 per cent pressure increase was 25.9.

It is also apparent from the table that mixtures of the chlorinated, unsaturated hydrocarbon with bromine give greater sensitization factors than an amount of bromine equal to or greater than the combined amount of the sensitizer. For example, sensitization factor for run 9 in which the combined amount of the sensitizers is 0.5 mole per cent, is 15.6 for a pressure increase of 25 per cent, whereas 0.5 mole per cent of bromine alone (run 4) gives a sensitization factor of only 6.2 for 25 per cent pressure increase.

In order to further demonstrate the remarkable increase in sensitization obtained by using a mixture of bromine and a chlorinated, unsaturated, aliphatic hydrocarbon, curves were plotted for several runs with time in minutes as abscissae, and pressure increase as ordinates.

Referring to Figure 1, curve 1 is a curve for the ilso-crotyl chloride. 7 Beta-methylallyl chloride.

ll'lrichlor ethylene.

20 average of several blank runs, data for which are given in the table under run 1. Curve 2 is a curve based on a run made using 0.25 mole per cent of bromine as sensitizer (run 3). Curve 3 is a curve for the run made using 1.0 mole per cent 5 of allyl chloride as sensitizer (run 6). Curve 4 30 pressure increase obtained without sensitizer at a selected time (from curve I), the pressure increase over that of the blank run caused in the same length of time by the presence of bromine alone (curve 2 minus curve l), and the pressure increase over that of the blank run caused in the same length of time by the presence of allyl chloride alone (curve 3 minus curve I), and plotting on the graph the figures obtained for a sufiicient number or difierent time periods to be able to draw a curve through the points. As an example,

referring to Figure 1, at a time two minutes after the beginning of the run pressure increase without any sensitizer (obtained from curve i is 2.15 per cent.- At the same time pressure increase for the run sensitized by bromine alone (obtained from curve 2) is 6.5 per cent; and the pressure increase for the run sensitized by allyl chloride alone (obtained from curve 3) is 3.4 per cent. Pressure increase due to the presence of bromine alone is therefore 6.5 per cent minus 2.15 per cent, or 4.35 per cent. Pressure increase due to allyl chloride alone is therefore 3.4 per cent minus 2.15 per cent, or 1.25 per cent. The pressure increase that might be expected from the combination of bromine and allyl chloride at a time two minutes after the beginning of the run is the sum of the pressure increase at that time Without sensitizer, and the pressure increase caused by each of the sensitizers when used alone, or 2.15 per cent plus 4.35 per cent plus 1.25 per cent. By looking on curve 4 it will be seen that two minutes after the beginning of the run the anticipated pressure increase is approximately 7.75 per cent.

Curve 5 represents the actual experimental data obtained in the run using the combination sensitizer. At a period two minutes after the beginning of the run the pressure increase was 22 per cent as against an expected increase of 7.75 per cent.

Considering the affect of the sensitizer in another way, in order to get a pressure increase of 25 per cent it was necessary to allow the reaction to continue for a period of approximately 2.7

0 minutes, whereas from the additive results of the individual sensitizers this pressure increasewould not be expected. until the reaction had continued for a period of approximately 10 minutes.

Referring now to Figure 2, the curves are similar to those in Figure 1, except that iso-crotyl chloride present in the amount of 0.5 mole per cent, instead of 1 per cent of allyl chloride, was tested alone, and in combination with bromine.

Figure 3 is similar to Figure 1 except that beta-methylallyl chloride present in the amount of 0.5 mole per cent, instead of 1 per cent of allyl chloride, was tested alone, and in combination with bromine.

Figure 4 is a similar to Figure 1, except that trlchlor ethylene in the amount of 0.5 mole per cent, instead of 1 per cent of allyl chloride, was tested alone, and in combination with bromine.

It is apparent from each set of curves that the experimental sensitization experienced from the combination of bromine and the unsaturated chlorinated hydrocarbon is considerably greater than could have been expected from the action of the bromine and the chlorinated, unsaturated hydrocarbon when used alone.

In order to further demonstrate the efiectiveness of mixtures of bromine and/or iodine with organic compounds containing a chlorinated, unsaturated, aliphatic group, Pennsylvania gas oil was cracked in a continuous laboratory cracking apparatus at a temperature of 525 C. and at approximately atmospheric pressure, both without any sensitizer and in the presence of 0.1 per cent by weight of bromine and 0.5 per cent by weight of allyl chloride. The charging rate was approximately 165 grams per hour. In the run in which no sensitizer was used 10.8 per cent by weight of the charge was cracked to liquid hydrocarbon boiling below 400 F. and 5.8 per cent by weight of the charge was cracked to gas. In the presence of the sensitizer, 15.2 per cent by weight of the charge was cracked to liquid hydrocarbon boiling below 400 F. and 10.4 per cent by weight of the charge was cracked to gas.

From the analyses of the reaction products appearing in the table it is apparent that the reaction is predominantly one of splitting the carbon to carbon bond as shown by the relatively large amount of unsaturated hydrocarbons and the small amount of hydrogen formed in the reaction. The nature of the reaction products obtained is essentially the same regardless of whether or not sensitizer is used.

The invention is useful in connection with known types of mineral oil cracking processes carried out in the absence of catalysts. It is also useful in catalytic cracking operations wherein a known solid comrninuted catalyst, such as natural or synthetic alumina-silica compositions, is used. The invention may also be used in connection with the cracking of gases to make unsaturated hydrocarbons, such as cracking of propane to propylene, butane to ethylene and propylene, and the cracking of liquid hydrocar bons to olefins and diolefins, such as butadiene.

It is claimed: 1. The method of cracking hydrocarbons comprising subjecting hydrocarbons to suitable cracking conditions of time, temperature and pressure in the presence of a small amount of a halogen selected from the group consisting of bromine and iodine and a small amount of an organic compound having a chlorinated, unsaturated, aliphatic group. v

2. Method in accordance with claim 1 in which the halogen is bromine and the organic compound is a chlorinated, unsaturated, aliphatic hydrocarbon.

3. Method in accordance with claim 1 in which the amount of halogen is at least .005 mole per cent and the amount of organic compound is at least .05 mole per cent.

4. Method in accordance with claim 1 in which th minimum amount of halogen and organic compound present is about .005 and .05 mole per cent, respectively, and the maximum combined amount of the two is about 5 mole per cent.

5. The method of cracking hydrocarbons containing at least 3 carbon atoms per molecule comprising subjecting said hydrocarbons to temperatures of approximately 375 to 750 C. in the presence of a small amount of bromine and a small amount of a chlorinated, unsaturated, hydrocarbon.

6. Method in accordance with claim 5 in which the chlorinated, unsaturated hydrocarbon is isocrotyl chloride.

7. Method in accordance with claim '5 in which th chlorinated, unsaturated hydrocarbon is allyl chloride.

8. Method in accordance with claim 5 in which the chlorinated, unsaturated hydrocarbon is methylallyl chloride.

9. Method in accordance with claim 5 in which the bromine is present in an amount of approximately .03 to 2 mole per cent and the chlorinated, unsaturated hydrocarbon is present in an amount of approximately 0.25 to 2 mole per cent.

10. The method of cracking hydrocarbons containing 3 or more carbon atoms per molecule comprising subjecting said hydrocarbons to suitable cracking conditions of time temperature and pressure in the presence of a small amount of bromine and a small amount of a chlorinated, unsaturated, aliphatic organic compound.

11. Method in accordance with claim 10 in which the temperature is approximately 375 to 750 C., the amount of bromine is .03 to 2 mole per cent and the amount of chlorinated compound is approximately 0.25 to 2 mole per cent.

12. Method in accordance with claim 10 in which the hydrocarbons subjected to cracking are composed chiefly of C4 hydrocarbons and the temperature of cracking is approximately 500 to 750 C.

13. The method of cracking normally liquid hydrocarbons to hydrocarbons boiling within the gasoline range comprising subjecting said hydrocarbons to suitable cracking conditions of time, temperature and pressure in the presence of bromine in the amount of approximately 0.1 per cent by weight and allyl chloride in the amount of approximately 0.5 per cent by weight.

HILLIS O. FOLKINS.

REFERENCES CITED UNITED STATES PATENTS Name Date Pier et al. Nov. 19. 1940 Number 

